""" Connected client management package.

This package store classes representing each client's role and the associated
sjRPC handler.
"""

import logging

from datetime import datetime

from sjrpc.utils import ConnectionProxy

from cloudcontrol.server.handlers import CCHandler, listed
from cloudcontrol.server.exceptions import RightError
from cloudcontrol.server.db import RemoteTag
from cloudcontrol.common.tql.db.tag import CallbackTag


class RegisteredCCHandler(CCHandler):

    """ Basic handler for all registered clients.
    """

    def __getitem__(self, name):
        self.client.top()
        return super(RegisteredCCHandler, self).__getitem__(name)

    def on_disconnect(self, conn):
        logging.info('Client %s disconnected', self.client.login)
        self.client.shutdown()

    def check(self, method, tql=None):
        """ Check if the client have access to this method.
        """
        allow = self.client.server.check(self.client.login, method, tql)
        if not allow:
            raise RightError('You are not allowed to do this action.')

    #
    # Tags registration handler functions:
    #

    @listed
    def tags_register(self, name, ttl=None, value=None):
        """ Register a new tag on the calling node.

        :param name: name of the tag to register
        :param ttl: ttl of the tag (or None if not applicable)
        :param value: value to fill the tag (optionnal)
        """
        self.client.tags_register(name, ttl, value)

    @listed
    def tags_unregister(self, name):
        """ Unregister a tag on the calling node.

        :param name: name of the tag to unregister
        """
        self.client.tags_unregister(name)

    @listed
    def tags_drop(self, name):
        """ Drop the tag value of the specified tag on the calling node.

        :param name: name of the tag to drop
        """
        self.client.tags_drop(name)

    @listed
    def tags_update(self, name, value, ttl=None):
        """ Update the value of the specified tag on the calling node.

        :param name: name of the tag to update
        :param value: new tag value
        :param ttl: new ttl value
        """
        self.client.tags_update(name, value, ttl)


class Client(object):

    """ Base class for all types cc-server clients.

    :param login: login of the client
    :param server: server instance
    :param connection: rpc connection to the client
    """

    ROLE = None
    RPC_HANDLER = RegisteredCCHandler
    KILL_ALREADY_CONNECTED = False

    roles = {}

    def __init__(self, login, server, connection):
        self._login = login
        self._server = server
        self._connection = connection
        self._handler = self.RPC_HANDLER(self)
        self._proxy = ConnectionProxy(self._connection.rpc)
        self._last_action = datetime.now()
        self._connection_date = datetime.now()
        self._tql_object = None

        # Remote tags registered:
        self._remote_tags = set()


    def _get_tql_object(self):
        """ Get the TQL object of the client from the cc-server tql database.
        """
        return self._server.db.get(self.login)

    @classmethod
    def register_client_class(cls, class_):
        """ Register a new client class.
        """
        cls.roles[class_.ROLE] = class_

    @classmethod
    def from_role(cls, role, login, server, connection):
        return cls.roles[role](login, server, connection)

    #
    # Properties
    #

    @property
    def proxy(self):
        """ Return a proxy to the rpc.
        """
        return self._proxy

    @property
    def object(self):
        """ Return the tql object of this client.
        """
        return self._tql_object

    @property
    def login(self):
        """ Return the login of this client.
        """
        return self._login

    @property
    def role(self):
        """ Return the role of this client.
        """
        return self.ROLE

    @property
    def server(self):
        """ Return the cc-server binded to this client.
        """
        return self._server

    @property
    def conn(self):
        """ Return the sjrpc connection to the client.
        """
        return self._connection

    @property
    def uptime(self):
        """ Get the uptime of the client connection in seconds.

        :return: uptime of the client
        """

        dt = datetime.now() - self._connection_date
        return dt.seconds + dt.days * 86400

    @property
    def idle(self):
        """ Get the idle time of the client connection in seconds.

        :return: idle of the client
        """
        dt = datetime.now() - self._last_action
        return dt.seconds + dt.days * 86400

    @property
    def ip(self):
        """ Get client remote ip address.
        """
        peer = self.conn.getpeername()
        return ':'.join(peer.split(':')[:-1])

    def attach(self):
        """ Attach the client to the server.
        """

        # Set the role's handler for the client:
        self.conn.rpc.set_handler(self._handler)

        # Register the client in tql database:
        self._tql_object = self._get_tql_object()

        # Register the server defined client tags:
        self._tql_object.register(CallbackTag('con', lambda: self.uptime, ttl=0))
        self._tql_object.register(CallbackTag('idle', lambda: self.idle, ttl=0))
        self._tql_object.register(CallbackTag('ip', lambda: self.ip))

    def shutdown(self):
        """ Shutdown the connection to the client.
        """
        # Unregister all remote tags:
        for tag in self._remote_tags.copy():
            self.tags_unregister(tag)

        # Unrefister all server defined client tags:
        self._tql_object.unregister('con')
        self._tql_object.unregister('idle')
        self._tql_object.unregister('ip')

        self._server.rpc.unregister(self.conn, shutdown=True)
        self._server.unregister(self)

    def top(self):
        """ Reset the "last action" date to now.
        """
        self._last_action = datetime.now()

    def async_remote_tags(self, watcher, robj, tags):
        """ Asynchronously update tags from the remote client using
            specified watcher.
        """
        watcher.register(self.conn, 'get_tags', tags, _data=robj)

    def tags_register(self, name, ttl=None, value=None):
        """ Register a new remote tag for the client.

        :param name: name of the tag to register
        :param ttl: TTL of the tag if applicable (None = no TTL, the tag will
                never expire)
        :param value: value of the tag
        """

        tag = RemoteTag(name, self.async_remote_tags, ttl=ttl)
        self._tql_object.register(tag)
        self._remote_tags.add(name)

    def tags_unregister(self, name):
        """
        Unregister a remote tag for the client.

        :param name: name of the tag to unregister
        """

        self._tql_object.unregister(name)
        self._remote_tags.discard(name)

    def tags_drop(self, name):
        """ Drop the cached value of a remote tag for the client.

        :param name: name of the tag to drop
        """
        tag = self._tql_object.get(name)
        if tag is not None:
            tag.invalidate()

    def tags_update(self, name, value=None, ttl=None):
        """ Update a remote tag.

        :param name: name of the tag to update
        :param value: new value of the tag
        :param ttl: new ttl of the tag
        """
        tag = self._tql_object.get(name)
        if tag is not None:
            if value is not None:
                tag.cached = value
            if ttl is not None:
                tag.ttl = ttl